Image copyright AFP/Getty Images Image caption Keytruda was developed by Merck and is taken orally
The US Food and Drug Administration (FDA) has approved the use of Keytruda as an adjuvant treatment for advanced kidney cancer.
The treatment has been approved to treat four common types of kidney cancer: advanced, metastatic, early or fast growing.
It works by blocking an enzyme called PD-1. This is associated with the T-cell receptor (TCR) pathways of the cancer cells.
Cancer researchers hope it will one day also be used as a first-line treatment.
It was developed by Merck and sold as Keytruda – the name of Merck’s version of the drug – and other companies, including Gilead Sciences, are developing similar treatments.
According to the National Cancer Institute, 10,000 new cases of kidney cancer are diagnosed in the UK each year.
Cardinal Health is the only UK supplier of Keytruda to clinical trial programmes.
T-cell receptor (TCR) pathway
TCR is a pathway, that allows T-cells – white blood cells – to locate and kill tumours and the five most commonly-used treatments for kidney cancer use an antibody to block this process.
Image copyright Getty Images Image caption Keytruda blocks an enzyme called PD-1
After current treatments are administered, CRS causes the body’s T-cells to “die”.
But, if the body’s immune system were to be told this T-cell pathway was ineffective, then a natural mechanism that controls and re-educates T-cells could be activated.
Studies have shown that they may have an anti-cancer effect – and therefore provide a longer-lasting protective effect than currently available treatment.
This is because according to Professor Alexander Bromberg, chair of the genetics and medicine division at the University of Nottingham, the mutation of PD-1 to decrease immune defences against tumours is only found in around 1% of patients.
This means by exposing patients to the PD-1 inhibitors, key pathways on T-cells that are normally targeted by the PD-1 proteins, are reinvigorated and instructed to get back to their normal jobs.
Image copyright Getty Images Image caption It is hoped Keytruda will eventually be used as a first-line treatment
Gilead Sciences was one of the first companies to receive FDA approval for a TCR antibody – simtuzumab – which they are licensed to develop for kidney cancer. The FDA approved it in January 2017.
However, the jury is still out as to whether other treatments involving the TCR pathway will prove to be as effective.
Mark Schoenberg, director of Oncology for Cardinal Health, said: “I expect TCR will progress from a limited use and trial in this indication to an overall ‘cure” status.
“We don’t know when but in the next two to five years, I think it will become the go-to approach for renal cell carcinoma.”
“Scientists have tried and failed to stop the cellular immune response [through treatments to stop the PD-1 inhibitors] for over 30 years.
“This FDA approval was a landmark moment for the field of immunotherapy and it brings hope that the future holds only greater progress.”